fix: requests and docker package compatibility

[notrepo05]

When running tile build --cache ./cache inside the sample directory, I encountered the following error:

request() got an unexpected keyword argument 'chunked'

this is due to an incompatibility between the requests and docker-py packages, see docker/docker-py#3113

After updating the constraint, the tile builds.

[cf-gitbot]

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The labels on this github issue will be updated when the story is started.